Splash type lubricating device for single cylinder horizontal internal-combustion engines



Feb.'16; 1954 H. s. BROWN SPLASH TYPE LUBRICATING DEVICE FOR 2 SINGLECYLINDER HORIZONTAL INTERNAL-COMBUSTION ENGINES Filed June 30, 1952 2Sheeps-Sheet 1 Feb. 16, 1954 H. s. BROWN 2,669,322

SPLASH TYPE LUBRICATING NGLE CYLINDER HORIZONTAL INT ENGINES Filed June50, 1952 DEVICE FOR SI L ERNA WNW

'Hugh www Patented Feb. 16, 1954 UNITED Vsrl-'iiT135 N T OFFICE SPLASHTYPE .LUBRICATING DEVICE,- FR SINGLE lCYLINDER HORIZONTAL vINTER-NAL-COMBUSTION ENGINES :Briggs- & Stratton Corporation,

Milwaukee,

, 6 Claims.

'I'his invention relates-to splash type lubricating devices lforinternal combustion engines and refers more particularly toa device` forthe linternal -lubrication of small single cylinder horizontal enginesin which the crankshaftis disposed-on a vertical axis. The verticaldisposition of -their crankshaftsadapts these engines fto many uses notAtoo wellserved by the more 'conventional upright` engines, rotary powerlawn mowers for instance. But in suchr horizontal engines-the crankcaseitself" must be specially. designed to prevent the supply oflinternal-lubrieating oil leaking out through `the lower crankshaftbearing, especially when the engine is idle.

Moreover unless vthe bottom ofthe crankcase is-disposed well below lthecylinder, the oil-level in the'crankcase wouldl oftenvbe above the`mouth of '.the cylinder, and oil v would then ,seepy through the pistonrings and, of courseyfoulftlie engine. It is, therefore, necessary, inan engine' having avertical crankshaft, to provide-anoilsump so disposedthat the level of the oilthereinlzisialways spaced below the vtop ofthe. lowermostf crankshaft bearing and, of course, lwell below;thecylinder. ABut this places the-oil in the sump beyond the,V reach of themoving engine parts `within the crankcase and .introduces the rproblemof feeding the oil to the cylinder Wall and `the crankshaft bearings.While a pump could-be used .for this. purpose, the added expenseentailed thereby practically rules it outas a solution tothe problem.

It is, therefore, an object of this invention-to provide a simpleinexpensive device whichy ,has none of the disadvantages of a pump, butinstead operates upon the time tested. splash. principle, forlubricatingthe moving .parts inside the ,crankcase ofan engine of the type having avertically disposed crankshaft.

v.Morespecifically it is an object ofnthis invention 4Ato provide aunitary oil slinger member rotatably mounted within the engine `with aportion thereof dipping into the oil bath anddriven from the enginetiming gears so as tothrowil out of the sump-and onto the moving engine,parts during operation ofthe engine.

` With the above and other objects in view, which. will appear asthe`description proceeds, this invention resides in the novelconstruction, .com-

bination and arrangement of parts substantially as hereinafter describedand more particularly den'ed bythe appended claims, it being understoodthat such changes in the precise embodiment' tof the hereindisclosed`yinvention maybe made ascome vwithin the scope oftheclaims *Theaccompanying drawings illustrate two complete -f examples'of thephysical embodiments ofthe invention constructed according 'to 'thebestfmod'es Aso far devised for the practicalapplication of theprinciples thereof, andin'which:

Figure l is an elevational view of a single cylind'erfgasoline engineembodying the lubricating deviceof this invention, a portion of thecrankcase'fand oil sump being broken away to better illustrate thelubricating device itself;

Figure* 2A is an enlarged sectional View of aportion of the engine, saidview corresponding'substantially to that portion of the engine in thearea shown broken away'in Figure 1;

Figure 3 is a bottom view of theoil slinger member per-se;

Figure 4 is a side view of a horizontal engine ofdifferentdesign fromthat vshown in Figure 1, illustrating the application of this inventiontheretoyparts of said View being broken away and in section and on theplane of the line 4 4 in Figure-5;

Figure 5 isa horizontal sectional view through Figure 4-on the plane ofthe line 5 5; and

vFigure 6 yis a detail sectional view taken through Figure 5 onthe planeof the-line 6 6.

' rReferring nowmore particularly to the accompanying' drawings linwhich like numerals designate like parts throughout the severalv views,and'fespecially to Sheet 1 thereof, the numeral 5 designates `generallya smally single cylinder internalcombustion engine of the type having acylinder -Gat one side of -a crankcase l, the axis ofthecylinder beinghorizontal, and having a crankshaft' 8 mounted on a vertical axis.

'Inside thecrankcase, as is conventional,- are a vnumber of moving partswhich are in need of lubricationV at all times during operation of theengine, including the lower crankshaft main bearing: 9;"the `uppercrankshaft. bearing il), the connecting'rod bearing Il, as well as thecylinder wall and ther wrist pin bearings "(not shown). TheA crankshaftprojects from the crankcase at botliits upper and 'lower ends, its upperendportionvhaving a starterxpulley 'i2xsecured thereto and' itslowerendportion I3 being' connectible with'a device tobe'drivenl by themotor.

vThe-lower wall I4 of the crankcase has a lboss [5in which the lower,main` bearing 9 is press fitted anclwhich carries an oil seal l'beneaththe' bearing. An annular space I'l aroundL thev crankshaft; between thelower main bearing and the oil seal, is communicated'with the interiorof thecrankcasethrough an upwardly opening well liinithe" boss. T'Theslighthead of oilv which accumulates in this well I8 and the space I1 isbeneficial in easing the friction at the heavily loaded lower mainbearing during starting and before a fresh supply of oil is brought tothe bearing through its oil hole I9.

The supply of lubricating oil for the engine is held in a sump 2G,formed as part of a substantially L-shaped shell 2l which is bolted tothe crankcase by screws 22 and closes what would be the bottom of thecrankcase ina vertical or upright engine. A gasket 25 between thecrankcase and the sump shell seals the connection between the two; and adrain plug 26, at the bottom of the outer side wall of the sump, enablesthe oil to be drained therefrom.

Oil from the sump is thrown onto the moving engine parts inside thecrankcase by means of the novel lubricating device of this invention,which in the Figure l embodiment comprises a unitary disc-like slingermember 21 and an intermediate gear 2t, which drives the slinger memberand is in turn driven by a gear 29 on the crankshaft. The gear 29 isjust above the main bearing and may be one of the timing gears of theengine.

Both the oil slinger and the intermediate gear are best molded ofplastic, preferably nylon. The slinger comprises a hub portion 30 havinga bore 3i therethrough to provide a bearing by means of which theslinger may be mounted, a frusto-conical medial portion 32 having gearteeth 33 on its cuter conical face, and a flat rim-like outer portion 34having three paddlelike projections 35 thereon which dip into the oil inthe sump and throw it onto the moving engine parts in the interior ofthe crankcase as the slinger rotates.

The slinger is freely rotatably mounted on a bearing structure,indicated generally by the numeral 36, which projects into the sump froma boss 31 on the side wall of the sump adjacent to the crankcase proper,with its axis disposed at an acute angle to the crankshaft axis so thatthe lower side of the slinger periphery is adjacent to the bottom of thesump, and the opposite side of its periphery is closer to thecrankshaft. The gear teeth 33 are on the bottom face of the slinger, i.e., the surface which faces the crankshaft.

The intermediate gear 28, like the slinger member, has a bored hub 4 land is mounted on a vertical bearing structure, designated generally bythe numeral 42, which projects up into the crankcase from a boss 43 onthe bottom crankcase wall, between the crankshaft and the slinger, sothat the driving gear has its axis parallel to that of the crankshaftand meshes with the gear 29 on the crankshaft and with the gear teeth 33on the bottom of the slinger.

The bearing structures by which the intermediate gear and the slingerare mounted include bored plugs ld which are press fitted intoaccurately bored apertures in the bosses Ii3 and 31 in the bottomcrankcase wall and the inner sump wall, respectively. Each plug has astub shaft l1 secured thereto by a screw 46, upon which the hubs of theslinger and gear are drectly journalled, the thrust bearings beingprovided by the adjacent ends of the plugs and heads 48 on the stubshafts. The employment of the plugs 4t eliminates the necessity forfacing operations on the crankcase and sump shell castings, and thusfacilitates manufacture of those parts.

It will be seen that the orbit of the paddleon the underside of theslinger member is such that, as the slinger rotates, the projections dipinto the oil in the sump, passing near to the bottom thereof so that theslinger will operate satisfactorily when the oil level in the sump islow, and then move upwardly toward the crankshaft, passing part way intothe interior of the crankcase itself. In the course of this orbit theprojections throw oil onto the moving parts in the interior of thecrankcase between and including the lower and upper crankshaft bearings9 and Hl, respectively, distributing oil substantially uniformly overall of them. After circulating over` the parts, the oil of coursereturns to the sump by gravity.

The modified embodiment of the invention illustrated in Figures fi, 5and 6 diners from that described principally in the way in which thesump for the lubricating oil is provided and the Way in which theslinger is driven. Thus, the oil sump instead of being provided by anL-shaped shell bolted to what normally is the bottom of the crankcase isformed by a cover plate 4S bolted to and closing what, in a verticalengine, is the side of the crankcase.

This cover plate t9 not only provides the base 5l) by which the engineis mounted in a horizontal position with its crankshaft axis vertical,but also has the lower main crankshaft bearing 5i and one of the camshaft bearings 52 therein. 'lo preclude the drainage of lubricant fromthe oil reservoir provided by the interior of the cover plate il@ thebearings 5l and 52 are located in upstanding bosses 53 and fait,respectively, the tops of which are well above the normal oil level.

The slinger 55 by which the oil is lifted from the sump or reservoir andthrown upwardly against the moving engine parts, as in the previouslydescribed embodiment of the invention, is mounted to rotate about aninclined axis so as to facilitate geared driving connection between theslinger and one of the timing gears 56, the bottom of the slinger beingprovided with gear teeth 51 for this purpose.

Attention is directed to the fact that no intermediate gear is necessaryin this embodiment of the invention. The specic construction of themounting for the slinger is also slightlyT different in this form of theinvention and consists merely of a tubular stub shaft tt bolted to anupstanding boss 59 which forms an integral part of the cover plate L39and on which the slinger is freely journalled.

From the foregoing description taken in connection with the accompanyingdrawings, it will be readily apparent to those skilled in this art thatthis invention provides a simple inexpensive means of reliablylubricating the moving parts of a small gasoline engine which, becauseof its being mounted with its crankshaft axis vertical cannot employ thecustomary splash system of oiling wherein the crankshaft itself or somemeans on the connecting rod dips down into the oil bath to throw the oilup onto the moving parts; and that it entirely eliminates the problem ofloss of lubricant through the bottom main bearing of such horizontalengines.

What I claim as my invention is:

1. In an internal combustion engine having a vertical crankshaftjournalled in axially aligned top and bottom bearings, a crankcase and ahorizontal cylinder at one side of the crankshaft: means defining an oilsump in open communication with the interior of the crankcase andhavlike projections ing a portion thereof near the bottom bearing of thecrankshaft; a rotatable oil slinger; means rotatably mounting theslinger with its axis disposed at an acute angle to an axis parallel tothat of the crankshaft and with part of the slinger disposed in thatportion of the oil sump near the bottom bearing and extending beneaththe normal oil level; and a geared driving connection between thecrankshaft and said rotatable slinger, so that the slinger rotatesduring operation of the engine and acts to throw oil from the sumpupwardly into the crankcase interior to lubricate the moving engineparts therein.

2.v In an internal combustion engine having a vertical crankshaft, acrankcase, axially aligned top and bottom bearings in which thecrankshaft is journalled, and a horizontal cylinder at one side of thecrankshaft: means defining an oil sump in open communication with theinterior of the crankcase, said oil sump having its bottom on a levelbelow that of the bottom bearing; a rotatable oil slinger; meansrotatably mounting said oil slinger with its axis disposed at an acuteangle to an axis parallel to that of the crankshaft and at that side ofthe crankshaft opposite the cylinder and with the lower portion of theslinger contiguous to the bottom of the oil sump so as to dip down intothe oil contained therein, the angular disposition of the slingerpositioning the same so that the oil flung upwardly thereby as theslinger rotates is thrown up into the interior of the crankcase andagainst the moving engine parts therein; and a driving connectionbetween the crankshaft and said rotatable slinger through which theslinger is rotated during operation of the engine.

3. In an internal combustion engine, the structure set forth in claim 2further characterized by the fact that the driving connection betweenthe crankshaft and the slinger comprises one of the timing gears of theengine, and gear teeth on the underside of the slinger meshing with saidtiming gear.

4. In an internal combustion engine of the horizontal type having acrankshaft and a cam shaft rotating on vertical axes, top and bottombearings in which the crankshaft and cam shaft are journalled, acrankcase and a horizontally disposed cylinder at one side of thecrankshaft: a removable pan-like cover plate closing the bottom of thecrankcase and defining an oil sump in open communication with theinterior of the crankcase; upstanding bosses rising from the bottom ofsaid cover plate in which the lower bearings for the crankshaft and ea-mshaft are mounted, the top of said bosses being a substantial distanceabove the bottom of said sump so as to be above the normal oil level;timing gears on the crankshaft and cam shaft directly above the tops ofsaid bosses; a rotatable oil slinger; means rotatably mounting theslinger with its axis at an angle to the axis of one of said shafts andat the side thereof opposite the cylinder 6 and with the lower portionof the rotatable slinger contiguous to the bottom of the oil sump andits upper portion contiguous to the timing gear on said shaft; and gearteeth on the slinger meshing with said timing gear so that duringoperation of the engine the slinger rotates to lift oil from the sumpand throw it upwardly into the interior of the crankcase.

5. In an internal combustion engine having a vertical crankshaft, acrankcase and a horizontal cylinder at one side of the crankcase: meansdefining an oil sump in open communication with the interior of thecrankcase, said oil sump having its bottom spaced a substantial distancebelow the cylinder; a rotatable oil slinger having a plurality ofvane-like projections thereon; means rotatably mounting said oil slingerat the side of the crankshaft opposite the cylinder with the axis of theslinger disposed at an acute angle to that of the crankshaft and withone side of the orbit of said projections adjacent to the bottom of thesump and the opposite side of said orbit closer to the axis of thecrankshaft and projecting partway into the crankcase and pointingtowards the cylinder so that upon rotation of the slinger oil is thrownfrom the sump into the crankcase interior toward the cylinder tolubricate the moving engine parts therein; and a driving connectionbetween the slinger and the crankshaft.

5. In an internal combustion engine of the type having a crankcase, acrankshaft rotatable on a vertical axis in main bearings mounted in thewalls of the crankcase, and an oil seal between the crankcase and thecrankshaft beneath the lowermost main bearing to prevent leakage of oilout of the interior of the crankcase: means defining an oil sump at oneside of the crankcase in open communication with the interior of thecrankcase and having its bottom below the level of said oil seal, sothat oil tends to drain from the crankcase into said sump, therebypreventing oil leakage out of the crankcase when the engine is idle; adisc-like rotatable oil slinger having a plurality of paddle-likeprojections spaced from its axis; means rotatably mounting said oilslinger with its axis disposed at an acute angle to that of thecrankshaft and with one side of the orbit of said projections adjacentto the bottom of said sump and the opposite side of said orbit closer tothe axis of the crankshaft; gear teeth on the surface of said oilslinger which faces the crankshaft; and a gear rotatably driven by thecrankshaft and meshing with the gear teeth on said oil slinger to rotatethe slinger during operation lof the engine and thus cause theprojections thereon to throw oil from the sump into the crankcaseinterior to lubricate the moving parts therein.

HUGH S. BROWN.

References Cited in the file of this patent UNITED STATES PATENTS

